1. Field of the Invention
The present invention relates to a burn-in socket, and more particularly to a socket having a hard stopper disposed within a base for precisely controlling a stroke of a contact mounted in the base.
2. Description of the Prior Art
Electronic packages are installed in a printed circuit board to construct a complete circuit with continuous functions. To ensure the functionality and reliability of the electronic package during service life, the electronic package must be tested before actual field application. The electronic package in the test usually undergoes an extended period of time at a high temperature, so that any earlier failure of a package can be detected accordingly. A so-called burn-in socket servers for connecting the electronic package to a test printed circuit board.
Tai Wan Pat No. M324868, issued to Hsiao on Jan. 1, 2008, discloses a typical burn-in socket. The burn-in socket includes a socket body with a plurality of contacts disposed therein, a cover rotatably coupled to the socket body and at least one slider received in the socket body. The socket body defines a receiving space for receiving an IC (integrated circuit) package, and the cover has a driving member. The slider has an end engaging with the driving member and another end extending toward the receiving space. When the burn-in socket is in a closed position, the slider supports the IC package to keep a reliable connection between the burn-in socket and the IC package. The cover comprises a lid that is formed with a frame configuration, a pressing member assembled to a bottom of the lid and a metal fastener on a top of the cover. When the burn-in socket is in a closed position, the cover presses downwardly an upper surface of the IC package to make an electrical connection between the contacts and the IC package. On that condition, the stroke of the contact is related to the configuration of the cover. As the cover is an assembly, a composite tolerance is created between adjacent members of the cover. As we all known, the number of the assembled members is increased, the composite tolerance of the assembly is increased. Thus the length of the contact may be designed in a wide range for the cover may have a large tolerance. As a result, it's difficult to control the stroke of the contact, so we need to provide a new burn-in socket to overcome this question.